Bipolar surgical instrument

ABSTRACT

A bipolar forceps includes a mechanical forceps including first and second shafts each having a jaw member extending from a distal end thereof and a handle disposed at a proximal end thereof for effecting movement of the jaw members relative to one another about a pivot. A disposable housing is configured to releasably couple to at least one of the shafts and an electrode assembly has electrodes releasably coupleable to the jaw members and adapted to connect to a source of electrosurgical energy to allow selective conduction of electrosurgical energy through tissue held therebetween to effect a tissue seal. An electrically conductive cutting element is disposed on at least one of the electrodes and is adapted to connect to the source of electrosurgical energy to allow selective conduction of electrosurgical energy through tissue held between the electrodes to effect a tissue cut.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a U.S. National Stage Application under 35U.S.C. § 371(a) of PCT/CN2013/080944 filed Aug. 7, 2013, the entirecontents of which are incorporated by reference herein.

BACKGROUND

1. Background of Related Art

The present disclosure relates to forceps used for open surgicalprocedures. More particularly, the present disclosure relates to abipolar forceps for treating tissue that is capable of sealing andcutting tissue.

2. Technical Field

A hemostat or forceps is a simple plier-like tool which uses mechanicalaction between its jaws to constrict vessels and is commonly used inopen surgical procedures to grasp, dissect and/or clamp tissue.Electrosurgical forceps utilize both mechanical clamping action andelectrical energy to effect hemostasis by heating the tissue and bloodvessels to coagulate, cauterize and/or seal tissue.

Certain surgical procedures require sealing and cutting blood vessels orvascular tissue. Several journal articles have disclosed methods forsealing small blood vessels using electrosurgery. An article entitledStudies on Coagulation and the Development of an Automatic ComputerizedBipolar Coagulator, J. Neurosurg., Volume 75, July 1991, describes abipolar coagulator which is used to seal small blood vessels. Thearticle states that it is not possible to safely coagulate arteries witha diameter larger than 2 to 2.5 mm. A second article is entitledAutomatically Controlled Bipolar Electrocoagulation—“COA-COMP”,Neurosurg. Rev. (1984), pp. 187-190, describes a method for terminatingelectrosurgical power to the vessel so that charring of the vessel wallscan be avoided.

By utilizing an electrosurgical forceps, a surgeon can either cauterize,coagulate/desiccate, reduce or slow bleeding and/or seal vessels bycontrolling the intensity, frequency and duration of the electrosurgicalenergy applied to the tissue. Generally, the electrical configuration ofelectrosurgical forceps can be categorized in two classifications: 1)monopolar electrosurgical forceps; and 2) bipolar electrosurgicalforceps.

Monopolar forceps utilize one active electrode associated with theclamping end effector and a remote patient return electrode or pad whichis typically attached externally to the patient. When theelectrosurgical energy is applied, the energy travels from the activeelectrode, to the surgical site, through the patient and to the returnelectrode.

Bipolar electrosurgical forceps utilize two generally opposingelectrodes which are disposed on the inner opposing surfaces of the endeffectors and which are both electrically coupled to an electrosurgicalgenerator. Each electrode is charged to a different electric potential.Since tissue is a conductor of electrical energy, when the effectors areutilized to grasp tissue therebetween, the electrical energy can beselectively transferred through the tissue.

SUMMARY

The present disclosure relates to forceps used for open surgicalprocedures. More particularly, the present disclosure relates to abipolar forceps for electrosurgically sealing and cutting tissue.

As is traditional, the term “distal” refers herein to an end of theapparatus that is farther from an operator, and the term “proximal”refers herein to the end of the electrosurgical forceps that is closerto the operator.

According to one aspect of the present disclosure, a bipolar forceps isprovided. The bipolar forceps generally includes a mechanical forceps, adisposable housing, an electrode assembly, and an electricallyconductive cutting element. The mechanical forceps includes first andsecond shafts each having a jaw member extending from its distal end anda handle disposed at its proximal end for effecting movement of the jawmembers relative to one another about a pivot from a first positionwherein the jaw members are disposed in spaced relation relative to oneanother to a second position wherein the jaw members cooperate to grasptissue. The disposable housing is configured to releasably couple to atleast one of the shafts. The electrode assembly has a first electrodereleasably coupleable to the jaw member of the first shaft and a secondelectrode releasably coupleable to the jaw member of the second shaft.Each electrode is adapted to connect to a source of electrosurgicalenergy to allow selective conduction of electrosurgical energy throughtissue to effect a tissue seal. The electrically conductive cuttingelement is disposed on one or both of the electrodes and is adapted toconnect to the source of electrosurgical energy to allow selectiveconduction of electrosurgical energy through tissue held between theelectrodes to effect a tissue cut.

Additionally or alternatively, one or both of the electrodes may includea channel defined along its length in vertical registration with theconductive cutting element and configured to engage the conductivecutting element when the jaw members are in the second position toprovide a gap distance between the electrodes.

Additionally or alternatively, the conductive cutting element may extendfrom the electrode thereof a distance between about 0.004″ and about0.010″ and the channel may define a depth of up to about 0.006″.

Additionally or alternatively, the extension distance of the conductivecutting element and the depth of the channel may cooperate to provide agap distance of about 0.004″.

Additionally or alternatively, the bipolar forceps may also include oneor more switches disposed through the housing and configured toselectively deliver electrosurgical energy to one or both of theelectrically conductive cutting element and the electrodes.

Additionally or alternatively, the switch may be configured toselectively deliver electrosurgical energy to the electrodes and theelectrically conductive cutting element in response to a singleactivation of the switch.

Additionally or alternatively, each of the electrodes may include anelectrically conductive sealing surface and at least one insulatingsubstrate.

Additionally or alternatively, a ratio of a prominence of the conductivecutting element to half a width of the electrically conductive sealingsurface of the electrode thereof is between about 0.25 and about 0.30.

Additionally or alternatively, the conductive cutting element may definea base portion and a body portion. The base portion may define a widthof at least 0.022″ and the body may define a minimum width of about0.015″.

Additionally or alternatively, the pivot may include a first surfaceconfigured to be received in an aperture defined through the first jawmember and a second surface configured to be received in an aperturedefined through the second jaw member.

Additionally or alternatively, each of the electrodes may include one ormore mechanical interfaces configured to complement a correspondingmechanical interface on one of the jaw members to releasably couple theelectrode to the respective jaw member.

Additionally or alternatively, the bipolar forceps may also include atissue stop disposed at a proximal end of one or both of the jaw membersand configured to maintain tissue between the electrodes during tissuesealing.

According to another aspect of the present disclosure, a bipolar forcepsis provided. The bipolar forceps generally includes a mechanicalforceps, a disposable housing, an electrode assembly, an electricallyconductive cutting element, one or more channels, and one or moreswitches. The mechanical forceps including first and second shafts eachhaving a jaw member extending from its distal end and a handle disposedat its proximal end for effecting movement of the jaw members relativeto one another about a pivot from a first position wherein the jawmembers are disposed in spaced relation relative to one another to asecond position wherein the jaw members cooperate to grasp tissue. Thedisposable housing has opposing halves configured to be releasablycoupled to each other to at least partially encompass one or both of theshafts. The electrode assembly has a first electrode releasablycoupleable to the jaw member of the first shaft and a second electrodereleasably coupleable to the jaw member of the second shaft. Eachelectrode is adapted to connect to a source of electrosurgical energy toallow selective conduction of electrosurgical energy through tissue toeffect a tissue seal. The electrically conductive cutting element isdisposed on one or both of the electrodes and is adapted to connect tothe source of electrosurgical energy to allow selective conduction ofelectrosurgical energy through tissue held between the electrodes toeffect a tissue cut. The channel is defined along a length of one orboth of electrodes and is in vertical registration with the conductivecutting element. The conductive cutting element is configured to engagethe channel when the jaw members are in the second position to provide agap distance between the electrodes. The switch is disposed on thehousing and is configured to selectively deliver electrosurgical energyto one or both of the electrically conductive cutting element and theelectrodes.

Additionally or alternatively, the switch may be configured toselectively deliver electrosurgical energy to the electrodes and theelectrically conductive cutting element in response to a singleactivation thereof.

Additionally or alternatively, the source of electrosurgical energy maybe configured to emit a first audible tone in response to completion ofthe tissue seal and a second audible tone in response to completion ofcutting of the sealed tissue.

Additionally or alternatively, at least a portion of the jaw members areseparated by the pivot.

According to another aspect of the present disclosure, a method ofmanufacturing forceps is provided. The method includes press-fitting afirst surface of a pivot into an aperture defined in a first shaftmember and pressing a second surface of the pivot into an aperturedefined through a first jaw member disposed on a second shaft member.The method also includes pressing a third surface of the pivot into anaperture defined through a second jaw member such that at least aportion of the pivot is disposed between at least a portion of the firstand second jaw members to provide separation therebetween. The methodalso includes coupling a distal end portion of the first shaft member tothe second jaw member.

Additionally or alternatively, the method may include coupling anelectrode to one or both of the jaw members. The electrode may includeone or more of a tissue sealing surface, an insulative substrate, and anelectrically conductive cutting element.

Additionally or alternatively, the method may also include welding thedistal end portion of the first shaft member to the second jaw member.

Additionally or alternatively, the method may also include coupling ahousing to one or both of the shaft members.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments of the subject instrument are described herein withreference to the drawings wherein:

FIG. 1 is a perspective view of a bipolar forceps according to anembodiment of the present disclosure including a mechanical forceps, adisposable housing, and an electrode assembly;

FIG. 2 is an enlarged, perspective view of a distal end of the bipolarforceps of FIG. 1;

FIG. 3 is a perspective view of the mechanical forceps of FIG. 1 withparts separated;

FIGS. 4 and 5 are greatly-enlarged, perspective views of electrodes ofthe electrode assembly of FIG. 1 with parts separated;

FIG. 6 is a perspective view of the bipolar forceps of FIG. 1 graspingtissue to effect a tissue seal; and

FIG. 7 is a transverse, cross-sectional view of another electrodeassembly configured for use with the bipolar forceps of FIG. 1.

DETAILED DESCRIPTION

Referring initially to FIGS. 1-3, a bipolar forceps 10 for use with openand/or laparoscopic surgical procedures includes a mechanical forceps 20having an end effector 24 and a disposable electrode assembly 21 (FIG.2). Mechanical forceps 20 includes first and second elongated shaftmembers 12 and 14. Elongated shaft member 12 includes proximal anddistal end portions 13 and 17, respectively, and elongated shaft member14 includes proximal and distal end portions 15 and 19, respectively.Disposed at proximal end portions 13, 15 of shaft members 12, 14 arehandle members 16 and 18, respectively, that are configured to allow auser to effect movement of at least one of the shaft members 12 and 14relative to the other. The end effector 24 includes opposing jaw members42, 44 that extend from the distal end portions 17 and 19 of shaftmembers 12 and 14, respectively. The jaw members 42, 44 are movablerelative to each other in response to movement of shaft members 12, 14.

Shaft members 12 and 14 are affixed to one another about a pivot 25 suchthat movement of shaft members 12, 14, imparts movement of the jawmembers 42, 44 from an open configuration (FIG. 2) wherein the jawmembers 44, 42 are disposed in spaced relation relative to one anotherto a clamping or closed configuration wherein the jaw members 42, 44cooperate to grasp tissue 150 therebetween (FIG. 6). In someembodiments, forceps 10 may be configured such that movement of one orboth of shaft members 12, 14 causes only one of the jaw members to movewith respect to the other jaw member. As further detailed below, pivot25 serves to sufficiently space the distal end portions 17, 19 of shaftmembers 12, 14, respectively, from each other to provide clearancetherebetween during movement of shaft members 12, 14 about pivot 25.

Each shaft member 12 and 14 also includes a ratchet portion 32 and 34,respectively. Each ratchet 32, 34 extends from the proximal end portion13, 15 of its respective shaft member 12, 14 towards the other ratchetin a generally vertically aligned manner such that the inner facingsurfaces of each ratchet 32 and 34 abut one another when the shaftmembers 12, 14 are approximated. Each ratchet 32 and 34 includes aplurality of flanges 31 and 33 (FIG. 3), respectively, that project fromthe inner facing surface of each ratchet 32 and 34 such that theratchets 32 and 34 may interlock at one or more positions. In someembodiments, each ratchet position holds a particular strain energy inthe shaft members 12 and 14 to impart a specific closure force to theend effector 24. At least one of the shaft members, e.g., shaft member12, includes a tang 99 that facilitates manipulation of forceps 20during surgical conditions.

A housing 70 having a pair of housing halves 70 a, 70 b is configured tomatingly engage and releasably encompass at least a portion of shaftmember 14. An interior of each of housing half 70 a, 70 b may include aplurality of cooperating mechanical interfaces disposed at variouspositions to effect mechanical coupling of housing halves 70 a, 70 b toform housing 70.

Forceps 10 includes an electrical cable 28 extending from housing 70configured to electrically connect forceps 10 to a source ofelectrosurgical energy, such as an electrosurgical generator 40, asshown in FIG. 1. One example of an electrosurgical generator is theLIGASURE® Vessel Sealing Generator and the ForceTriad® Generator sold byCovidien.

With reference to FIG. 3, jaw members 42 and 44 include flanges 36 and38, respectively, extending proximally from a distal portion thereof.Each of flanges 36 and 38 defines a bearing aperture 29 c and 29 b,respectively, defined therethrough. Pivot 25 includes a press-fitsurface 25 a and a pair of bearing surfaces 25 b and 25 c that extendfrom opposing sides of a clearance surface 25 d. Press-fit surface 25 ais configured to be press-fit into an aperture 29 a defined through adistal end portion 17 of shaft member 12. Bearing surfaces 25 b and 25 care configured to be pressed into bearing apertures 29 b and 29 c,respectively, defined through flanges 38 and 36, respectively. Onceshaft members 12, 14 are coupled together about pivot 25, pivot may besecured to shaft members 12, 14 via a suitable welding technique. Shaftmembers 12, 14 are configured to rotate about pivot 25 such that bearingapertures 29 b, 29 c pivot about respective bearing surfaces 25 b, 25 c.

In some embodiments, mechanical forceps 20 may be assembled as follows:Press-fit surface 25 a is inserted through aperture 29 b such thatpress-fit surface 25 a is press-fit into aperture 29 a defined throughdistal end portion 17 of shaft member 12 and bearing surface 25 b ispressed into bearing aperture 29 b defined through flange 38 such thatclearance surface 25 d engages a surface of distal end portion 17 thatsurrounds bearing aperture 29 b. Bearing surface 25 c is pressed intobearing aperture 29 c defined through flange 36 of jaw member 42 suchthat clearance surface 25 d engages a surface of flange 36 thatsurrounds bearing aperture 29 c and is disposed between flanges 36 and38. The term “pressed” may refer to any suitable coupling of bearingsurfaces 25 b, 25 c to bearing apertures 29 b, 29 c, respectively, suchas an interface-fit (press-fit, friction-fit, etc.), a transition fit,or a sliding fit. Clearance surface 25 d serves to maintain clearancebetween flanges 36, 38 during pivoting of jaw members 42, 44 about pivotbetween the open and closed configurations. Clearance surface 25 d alsoserves to limit the distance by which the flanges 36, 38 may becompressed together during assembly of mechanical forceps 20. Once pivot25 is properly fitted within apertures 29 a, 29 b, and 29 c, asdescribed hereinabove, jaw member 42 may be coupled to distal endportion 17 of shaft member 12. For example, jaw member 42 may be weldedalong one or more lap joints to distal end portion 17 of shaft member12. In some embodiments, jaw member 42 may be monolithically formed withshaft member 12 as similarly depicted with respect to jaw member 44 andshaft member 14 (FIG. 3). The term “pressing” refers herein to anysuitable interface-fit between

Referring to FIG. 2, disposable electrode assembly 21 includes a pair ofelectrodes 110, 120 configured to releasably couple to mechanicalforceps 20, as detailed below. With reference to FIG. 5, electrode 110includes an electrically conductive sealing surface 116 configured toconduct electrosurgical energy through tissue to effect a tissue seal,an electrically conductive cutting element 85 configured to cut tissueby conducting electrosurgical energy therethrough, and a pair ofelectrically insulative substrates 109 and 111. In some embodiments,substrates 109, 111 may be made from an injection molded plasticmaterial. Substrate 109 is disposed between sealing surface 116 andcutting element 85 and serves to electrically insulate sealing surface116 from cutting element 85. Substrate 111 serves to electricallyinsulate jaw member 44 from sealing surface 116 and cutting element 85.A cutting element channel 58 a is defined in sealing surface 116 and isconfigured to align in vertical registration with a correspondingcutting element channel 58 b defined in substrate 109. Cutting element85 is disposed between substrate 109 and substrate 111 and extendsthrough cutting element channels 58 a and 58 b such that cutting element85 extends beyond or is raised above a tissue contacting portion ofsealing surface 116. Substrate 109 includes retention features 54 formedthereon configured to be received within corresponding retainingapertures 56 disposed along an outer periphery of sealing surface 116(FIG. 5) to couple sealing surface 116 to substrate 109. During assemblyof electrode 110, sealing surface 116 is coupled to substrate 109 andcutting element 85 is disposed between substrate 109 and substrate 111such that cutting element 85 extends through channels 58 a, 58 b.Substrate 111 is subsequently overmolded to the retention features 54formed on substrate 109 to secure sealing surface 116 to substrate 111.

Substrate 111 includes a plurality of bifurcated anchor members 112extending therefrom that are configured to compress during insertioninto a corresponding plurality of sockets 43 disposed at least partiallythrough an inner facing surface 47 (FIG. 3) of jaw member 44 andsubsequently expand to releasably engage corresponding sockets 43 afterinsertion to couple electrode 110 to inner facing surface 47. Substrate111 also includes an alignment pin 128 (FIG. 4) that is configured toengage an aperture 65 disposed at least partially through inner facingsurface 47 of jaw member 44 to ensure proper alignment of electrode 110with jaw member 44 during assembly. Sealing surface 116 includes atermination 155 extending from a proximal end thereof configured toelectrically connect to a wire 61 (FIG. 2) extending from a distal endof housing 70. Cutting element 85 includes a termination 165 extendingfrom a proximal end thereof and configured to electrically connect to awire 62 extending from a distal end of housing 70 (FIG. 2).

As shown in FIGS. 2 and 5, a proximal end of substrate 111 forms a pairof opposing tissue stops 113 a, 113 b extending therefrom that serve tomaintain tissue between sealing surfaces 116, 126 during tissue sealingand prevent tissue from entering the pivot area (e.g., where shaftmembers 12, 14 rotate about pivot 25). As shown in FIG. 2, tissue stops113 a, 113 b are suitably spaced from each other to accommodate themovement of jaw member 44 therebetween relative to jaw member 42. Atleast one longitudinal indicator 114 (FIG. 5) is formed along thelongitudinal length of substrate 111 and includes a distal end 114 athat aligns laterally with a distal end of cutting element 85 so thatwhen the jaw members 42, 44 are in the closed configuration (FIG. 6) andthe cutting element 85 may not be visible, the user may reference distalend 114 a of indicator 114 to determine the position of cutting element85 relative to tissue grasped between the jaw members 42, 44 prior toenergizing cutting element 85 to effect a tissue cut.

Substantially as described above with respect to electrode 110, and withreference to FIG. 4, electrode 120 includes an electrically conductivesealing surface 126 configured to conduct electrosurgical energy throughtissue and a pair of electrically insulative substrates 119 and 121. Insome embodiments, substrates 119, 121 are made from an injection moldedplastic material. Substrate 121 serves to electrically insulate jawmember 42 from sealing surface 126. A channel 59 a is defined in sealingsurface 126 and is configured to align in vertical registration with acorresponding gap stop channel 59 b defined in substrate 119. Gap stopchannel 59 b may be formed along substrate 119 such that upon movementof the jaw members 42, 44 to the closed configuration (FIG. 6), cuttingelement 85 extends through channel 59 a in sealing surface 126 andengages gap stop channel 59 b to prohibit further approximation ofsealing surfaces 116, 126, as further detailed below. Substrate 119includes retention features 64 formed thereon configured to be receivedwithin corresponding retaining apertures 66 disposed along an outerperiphery of sealing surface 126 (FIG. 4) to couple sealing surface 126to substrate 119. During assembly of electrode 120, sealing surface 126is coupled to substrate 119 and substrate 121 is subsequently overmoldedto the retention features 64 formed on substrate 119 to secure sealingsurface 126 to substrate 121.

Substrate 121 includes a plurality of bifurcated anchor members 122extending therefrom that are configured to compress during insertioninto a corresponding plurality of sockets 41 disposed at least partiallythrough an inner facing surface 45 (FIG. 3) of jaw member 42 andsubsequently expand to releasably engage corresponding sockets 41 afterinsertion to couple electrode 120 to inner facing surface 45. Substrate121 also includes an alignment pin 124 (FIG. 4) that is configured toengage an aperture 67 disposed at least partially through inner facingsurface 45 of jaw member 42 (FIG. 3) to ensure proper alignment ofelectrode 120 with jaw member 42 during assembly. Sealing surface 126includes a termination 145 configured to electrically connect to a wire63 disposed therein (FIG. 3). In some embodiments, electrodes 110, 120may be coupled to jaw members 42, 44 before, during, or after assemblyof mechanical forceps 20 described above with reference to FIG. 3.

Substrate 121 may also include at least one longitudinal indicator 117(FIG. 4) formed along the longitudinal length thereof to complementlongitudinal indicator 114 of substrate 111. Longitudinal indicator 117includes a distal end 117 a that aligns laterally with a distal end ofcutting element 85 so that when the jaw members 42, 44 are in the closedconfiguration (FIG. 6) and the cutting element 85 may not be visible,the user may reference distal end 117 a of indicator 117 to determinethe position of cutting element 85 relative to tissue grasped betweenthe jaw members 42, 44 prior to energizing cutting element 85 to effecta tissue cut.

To electrically control the end effector 24, the housing 70 supports atleast one depressible activation button 50 (FIG. 1) that is operable bythe user to actuate a corresponding electrical switch (not shown)disposed within housing 70 and electrically interconnected with wires61, 62, and 63. Button 50 may itself be an electrical switch that servesto initiate and terminate delivery of electrosurgical energy from thegenerator 40 to sealing surfaces 116, 126 to effect a tissue seal and tocutting element 85 to cut sealed tissue. Wires 61, 62, and 63 arebundled to form cable 28, which extends through housing 70 andterminates at a suitable connector (not shown) configured tomechanically and electrically couple to the generator 40.

FIG. 6 shows bipolar forceps 10 during use wherein the shaft members 12and 14 are approximated to apply clamping force to tissue 150 and toeffect a tissue seal. Once sealed, tissue 150 may be cut along thetissue seal by energizing cutting element 85. Cutting element 85 servesto provide a gap distance “G” (FIG. 6) between sealing surfaces 116, 126during tissue sealing and to cut the tissue along the seal. In someembodiments, cutting element 85 is made from an insulative ornon-conductive material and includes a conductive coating disposedthereon. When sealing surfaces 116, 126 are energized during tissuesealing, cutting element 85 may not necessarily be energized so thatcurrent is concentrated between sealing surfaces 116, 126 to effectivelyseal the tissue.

Tissue seal effectiveness may be influenced by the pressure applied totissue between jaw members 44, 42 and the gap distance between sealingsurfaces 116, 126 (FIG. 6) during tissue sealing. Jaw members 42, 44 maybe pivoted about pivot 25 to move jaw members 42, 44 to the closedconfiguration of FIG. 6 wherein sealing surfaces 116, 126 provide apressure to tissue grasped therebetween. In some embodiments, to providean effective seal, a pressure within a range between about 3 kg/cm² toabout 16 kg/cm² is applied to tissue and, in other embodiments, apressure within a range between about 7 kg/cm² to about 13 kg/cm² isapplied to the tissue. In the closed configuration of jaw members 42,44, gap distance “G” may be maintained between sealing surfaces 116, 126by cutting element 85. Cutting element 85 extends through channel 59 aof sealing surface 126 and engages stop gap channel 59 b (FIG. 4)defined in substrate 119 to prohibit further approximation of sealingsurfaces 116, 126 and to create gap distance “G” (FIG. 6) betweensealing surface 116, 126 during tissue sealing. In some embodiments, toprovide an effective tissue seal, an appropriate gap distance of about0.001 inches to about 0.010 inches and, in other embodiments, betweenabout 0.002 and about 0.005 inches may be provided.

Cutting element 85 may be independently activated by the surgeon orautomatically activated by generator 40 once tissue sealing is complete.Generator 40 may employ a suitable safety algorithm to assure that anaccurate and complete tissue seal is formed before cutting element 85 isenergized to cut tissue. An audible or visual indicator (not shown) maybe employed to assure the surgeon that an effective tissue seal has beenachieved and the surgeon may be required to press button 50 again ordeactivate a safety mechanism (not shown) to initiate tissue cutting.

In some embodiments, tissue sealing and tissue cutting may be completedusing a single activation step without the need to re-grasp tissuebetween sealing surfaces 116, 126 or without the need to perform asecond activation step (e.g., pressing button 50 disposed on housing 70)to initiate tissue cutting following completion of tissue sealing. Forexample, generator 40 may be configured with a suitable tissue sealingand/or tissue cutting control algorithm that allows tissue sealing andtissue cutting to be performed in response to a single activation step,i.e., the pressing of button 50 disposed on housing 70. In thisscenario, the tissue sealing process is started and completed followingactivation of button 50. A first audible tone may be emitted bygenerator 40 to signal the completion of the tissue sealing process.Generator 40 next initiates the tissue cutting process to cut thepreviously sealed tissue and, upon completion of the tissue cuttingprocess, emits a second audible tone (e.g., a tone different than thefirst tone) to signal the completion of the tissue cutting process. Insome embodiments, generator 40 includes a suitable user interfaceconfigured to allow a user to switch generator 40 between a tissue cutonly mode, a tissue seal only mode, or a combined tissue cut and tissueseal mode that allows tissue sealing and cutting in response to a singleactivation step, as described above.

According to one aspect of the present disclosure, a method ofmanufacturing a forceps (e.g., mechanical forceps 20) includespress-fitting a first surface of a pivot (e.g., pivot 25) into anaperture defined in a first shaft member (e.g., shaft member 12) andpressing a second surface of the pivot into an aperture defined througha first jaw member (e.g., jaw member 44) disposed on a second shaftmember (e.g., shaft member 14). The method also includes pressing athird surface of the pivot into an aperture defined through a second jawmember (e.g., jaw member 42) such that the pivot is disposed to provideseparation between the jaw members. The method also includes coupling adistal end portion of the first shaft member to the second jaw member.The method may also include coupling an electrode (e.g., electrode 110or 120) to at least one of the jaw members. The electrode may include atleast one of a tissue sealing surface (e.g., tissue sealing surface 116or 126), an insulative substrate (e.g., substrate 109, 111, 119, or 121)and an electrically conductive cutting element (e.g., cutting element85). The method may also include welding the distal end portion of thefirst shaft member to the second jaw member. The method may also includecoupling a housing (e.g., housing 70) to at least one of the shaftmembers.

Turning now to FIG. 7, another electrode assembly 210 provided inaccordance with the present disclosure and configured for use withbipolar forceps 10 (FIG. 1) is shown. Electrode assembly 210 may includeany or all of the features of electrode assembly 21 (FIGS. 2, 4, and 5),described above. Likewise, electrode assembly 21 (FIGS. 2, 4, and 5) mayincorporate any or all of the features of electrode assembly 210.Electrode assembly 210 is described in detail below.

Electrode assembly 210 generally includes first and second electrodes1100, 1200, respectively. First electrode 1100 includes an electricallyconductive sealing surface 1160 configured to conduct electrosurgicalenergy through tissue to effect a tissue seal, an electricallyconductive cutting element 850 configured to cut tissue by conductingelectrosurgical energy therethrough, and a pair of electricallyinsulative substrates 1090 and 1110. Substrate 1090 is disposed betweensealing surface 1160 and cutting element 850 and serves to electricallyinsulate sealing surface 1160 from cutting element 850. Substrate 1110serves to electrically insulate jaw member 42 from sealing surface 1160and cutting element 850. Cutting element 850 is disposed within andextends from substrate 1090 such that cutting element 850 extends beyondor is raised above a tissue contacting portion of sealing surface 1160.More specifically, cutting element 850 may be configured to extend fromthe tissue contacting portion of sealing surface 1160 between about0.004″ and about 0.010″. That is, cutting element 850 may define aprominence “P” of between about 0.004″ and about 0.010″. Further, theratio of the prominence “P” of cutting element 850 to the width “W” ofeach portion of sealing surface 1160 may be between about 0.25 to about0.30. For example, for a width “W” of about 0.25″, the prominence “P”may be about 0.007″. Other prominence configurations are alsocontemplated. It has been found that a prominence “P” of between about0.004″ and about 0.010″ provides increased cut performance, particularlywith respect to thicker and/or more fatty tissue.

Cutting element 850 includes a base portion 852 substantially disposedwithin substrate 1090, and a body portion 854 extending from substrate1090 towards the opposed jaw member 42. Base portion 852 defines agreater width than body portion 854 to inhibit cutting element 850 fromsinking into substrate 1090, e.g., to inhibit variation in theprominence of cutting element 850. The width of base portion 852 may beat least about 0.022″, while the minimum width of body portion 854 maybe about 0.015″, although other configurations are also contemplated.

Electrode 1200 includes an electrically conductive sealing surface 1260configured to conduct electrosurgical energy through tissue and a pairof electrically insulative substrates 1290 and 1210. Substrate 1210serves to electrically insulate jaw member 44 from sealing surface 1260.Substrate 1290 extends into a channel 590 a defined in sealing surface1260 and is configured to align in vertical registration with cuttingelement 850 to electrically insulate cutting element 850 from sealingsurface 1260. Substrate 1290 may be recessed relative to a tissuecontacting portion of sealing surface 1260 or may be substantially flushtherewith. More specifically, substrate 1290 may be recessed withinchannel 590 a and relative to the tissue contacting portion of sealingsurface 1260 by up to about 0.006″, although no recess is alsocontemplated. Further, the recessed distance of substrate 1290 (or lackor recession of substrate 1290) and the prominence of cutting element850 may cooperate to establish a minimum gap distance between electrodes1100, 1200 when approximated relative to one another. The minimum gapdistance may be about 0.004″, although other gap distances are alsocontemplated. Thus, for example, the prominence of cutting element 850may be about 0.007″ and the recessed distance of substrate 1190 may beabout 0.003″ to establish a minimum gap distance of about 0.004″,although other configurations are also contemplated. As can beappreciated, this combination of a recessed substrate 1190 and prominentcutting member 850 provides the benefit or a prominent cutting member850, as detailed above, while maintaining a desired minimum gapdistance.

While several embodiments of the disclosure have been shown in thedrawings, it is not intended that the disclosure be limited thereto, asit is intended that the disclosure be as broad in scope as the art willallow and that the specification be read likewise. Therefore, the abovedescription should not be construed as limiting, but merely as examplesof particular embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

Although the foregoing disclosure has been described in some detail byway of illustration and example, for purposes of clarity orunderstanding, it will be obvious that certain changes and modificationsmay be practiced within the scope of the appended claims.

What is claimed is:
 1. A bipolar forceps, comprising: a mechanicalforceps including first and second shafts each having a jaw memberextending from a distal end thereof and a handle disposed at a proximalend thereof for effecting movement of the jaw members relative to oneanother about a pivot from a first position wherein the jaw members aredisposed in spaced relation relative to one another to a second positionwherein the jaw members cooperate to grasp tissue therebetween; adisposable housing configured to releasably couple to at least one ofthe shafts; an electrode assembly having a first electrode releasablycoupleable to the jaw member of the first shaft and a second electrodereleasably coupleable to the jaw member of the second shaft, eachelectrode having an electrically conductive sealing surface adapted toconnect to a source of electrosurgical energy to allow selectiveconduction of electrosurgical energy through tissue held therebetween toeffect a tissue seal; an electrically conductive cutting elementdisposed on the first electrode and adapted to connect to the source ofelectrosurgical energy to allow selective conduction of electrosurgicalenergy through tissue held between the electrodes to effect a tissuecut; and a first insulative substrate configured to releasably couplethe first electrode to the jaw member of the first shaft and a secondinsulative substrate different than the first insulative substratedisposed between the first insulative substrate and the electricallyconductive sealing surface of the first electrode, the first insulativesubstrate extending along a side surface of the second insulativesubstrate, the conductive cutting element disposed between the first andsecond insulative substrates and extending through a longitudinalchannel defined by the second insulative substrate and a longitudinalchannel defined by the electrically conductive sealing surface of thefirst electrode when the jaw members are disposed in the first position.2. The bipolar forceps according to claim 1, wherein the secondelectrode includes an insulative substrate defining a longitudinalchannel disposed in vertical registration with the conductive cuttingelement and configured to engage the conductive cutting element when thejaw members are in the second position to provide a gap distance betweenthe electrodes.
 3. The bipolar forceps according to claim 2, wherein theconductive cutting element extends from the first electrode a distancebetween about 0.004″ and about 0.010″ and wherein the longitudinalchannel defined by the insulative substrate of the second electrodedefines a depth of up to about 0.006″.
 4. The bipolar forceps accordingto claim 3, wherein the extension distance of the conductive cuttingelement and the depth of the longitudinal channel defined by theinsulative substrate of the second electrode cooperate to provide a gapdistance of about 0.004″.
 5. The bipolar forceps according to claim 1,further comprising at least one switch disposed through the housingconfigured to selectively deliver electrosurgical energy to at least oneof the electrically conductive cutting element or the electricallyconductive sealing surfaces.
 6. The bipolar forceps according to claim5, wherein the switch is configured to selectively deliverelectrosurgical energy to the electrically conductive sealing surfacesand the electrically conductive cutting element in response to a singleactivation thereof.
 7. The bipolar forceps according to claim 1, whereina ratio of a prominence of the conductive cutting element to half awidth of the electrically conductive sealing surface of the firstelectrode is between about 0.25 and about 0.30.
 8. The bipolar forcepsaccording to claim 1, wherein the conductive cutting element defines abase portion and a body portion, the base portion defining a width of atleast 0.022″ and the body defining a minimum width of about 0.015″. 9.The bipolar forceps according to claim 1, wherein the pivot includes afirst surface configured to be received in an aperture defined throughthe first jaw member and a second surface configured to be received inan aperture defined through the second jaw member.
 10. The bipolarforceps according to claim 1, wherein each of the electrodes includes atleast one mechanical interface configured to complement a correspondingmechanical interface on one of the jaw members to releasably couple theelectrode to the respective jaw member.
 11. The bipolar forcepsaccording to claim 1, further comprising a tissue stop disposed at aproximal end of at least one of the jaw members and configured tomaintain tissue between the electrodes during tissue sealing.
 12. Thebipolar forceps according to claim 1, wherein at least a portion of thesecond insulative substrate is disposed within the longitudinal channeldefined by the electrically conductive sealing surface of the firstelectrode.
 13. The bipolar forceps according to claim 1, furthercomprising a tissue stop disposed at a proximal portion of at least oneof the jaw members and configured to prevent tissue from entering thepivot.
 14. A bipolar forceps, comprising: a mechanical forceps includingfirst and second shafts each having a jaw member extending from a distalend thereof and a handle disposed at a proximal end thereof foreffecting movement of the jaw members relative to one another about apivot from a first position wherein the jaw members are disposed inspaced relation relative to one another to a second position wherein thejaw members cooperate to grasp tissue therebetween; a disposable housinghaving opposing halves configured to be releasably coupled to each otherto at least partially encompass at least one of the shafts; an electrodeassembly having a first electrode releasably coupleable to the jawmember of the first shaft and a second electrode releasably coupleableto the jaw member of the second shaft, each electrode having anelectrically conductive sealing surface defining a longitudinal channeland adapted to connect to a source of electrosurgical energy to allowselective conduction of electrosurgical energy through tissue heldtherebetween to effect a tissue seal; an electrically conductive cuttingelement disposed on the first electrode and adapted to connect to thesource of electrosurgical energy to allow selective conduction ofelectrosurgical energy through tissue held between the electrodes toeffect a tissue cut; each of the first and second electrodes including afirst insulative substrate configured to releasably couple the electrodeto one of the jaw members and a second insulative substrate differentthan the first insulative substrate disposed between the firstinsulative substrate and the electrically conductive sealing surface,the first insulative substrate disposed on a side surface of the secondinsulative substrate, the electrically conductive cutting elementdisposed between the first and second insulative substrates of the firstelectrode and extending through a longitudinal channel defined by thesecond insulative substrate of the first electrode and the longitudinalchannel defined by the electrically conductive sealing surface of thefirst electrode when the jaw members are disposed in the first position,wherein the electrically conductive cutting element extends through thelongitudinal channel defined by the electrically conductive sealingsurface of the second electrode and into engagement with a longitudinalchannel defined by the second insulative substrate of the secondelectrode to control a gap between the jaw members when the jaw membersare in the second position; and at least one switch disposed on thehousing configured to selectively deliver electrosurgical energy to atleast one of the electrically conductive cutting element and theelectrodes.
 15. The bipolar forceps according to claim 14, wherein theswitch is configured to selectively deliver electrosurgical energy tothe electrically conductive sealing surfaces and the electricallyconductive cutting element in response to a single activation thereof.16. The bipolar forceps according to claim 15, wherein the source ofelectrosurgical energy is configured to emit a first audible tone inresponse to completion of the tissue seal and a second audible tone inresponse to completion of cutting of the sealed tissue.
 17. The bipolarforceps according to claim 14, wherein at least a portion of the jawmembers are separated by the pivot.
 18. A bipolar forceps, comprising: afirst jaw member coupled to a first shaft and a second jaw coupled to asecond shaft, the first and second shafts movable about a pivot to movethe first and second jaw members relative to each other between an openposition and a closed position; a first electrode releasably coupled tothe first jaw member and a second electrode releasably coupled to thesecond jaw member, the first electrode including: a tissue sealingsurface defining a longitudinal channel and adapted to connect to asource of electrosurgical energy; a first insulator configured toreleasably couple the tissue sealing surface to the first jaw member;and a second insulator different than the first insulator defining alongitudinal channel and disposed at least partially within thelongitudinal channel defined by the tissue sealing surface, the firstinsulator extending along a side surface of the second insulator; and acutting element disposed on the first jaw member and configured toelectrosurgically cut tissue, the cutting element extending through thelongitudinal channel defined by the second insulator and thelongitudinal channel defined by the tissue sealing surface of the firstelectrode.
 19. The bipolar forceps according to claim 18, wherein thecutting element extends through the longitudinal channel defined by thesecond insulator and the longitudinal channel defined by the tissuesealing surface of the first electrode when the jaw members are in theopen position.
 20. The bipolar forceps according to claim 1, wherein thesecond insulative substrate is disposed adjacent to the electricallyconductive cutting element and between the electrically conductivecutting element and the electrically conductive sealing surface of thefirst electrode to insulate the electrically conductive cutting elementfrom the electrically conductive sealing surface of the first electrode.